The disclosure is directed to an electrophotographic digital printer for printing to a recording medium with toner particles and a corresponding method.
Given electrophotographic digital printers, a latent charge image of an image carrier is inked with toner (for example liquid toner or dry toner). The toner image that is created in such a manner is typically transferred indirectly to a recording medium via a transfer station. In this transfer step, an electric field is used in order to print the toner image onto the recording medium.
Cardboard (e.g., for the manufacture of a folding cardboard box) may be used as a recording medium, for example. Cardboard is most often finished only on the top side or front side, for example via repeated coating processing, wherein the back side is typically coated only once or not at all. The back side of cardboard thus most often has a rough or uneven surface. Furthermore, cardboard typically has a substantial thickness (of up to 500 for example).
Such recording media with an inhomogeneous back side may interfere with the transfer step (assisted by an electric field) of a toner image onto the top side of the recording medium. In particular, the print quality of a print image on the top side of the recording medium may be reduced due to an inhomogeneous back side. Furthermore, the transfer step may be negatively affected by the thickness of the cardboard.
U.S. Pat. No. 6,395,387B1 describes a two-sided, coated, transparent recording medium for an electrophotographic printer. JP2004-054163A describes a printer with means to adjust the moisture of a recording medium. US2009/0080956A1 describes a printer in which a conductive film is applied onto the surface of a recording medium. JP H01-233462A describes a printer in which a fluid is applied onto the surface of an electrostatic recording medium.